The present invention relates to a process for decaffeinating coffee extracts, and the like. More particularly, liquid coffee extracts, and the like, are decaffeinated using solvent systems which comprise benzyl alcohol.
In coffee decaffeination processes, either the beans, themselves, or extracts prepared from roasted coffee beans are contacted with solvents which dissolve and remove the caffeine. A wide variety of solvent systems have been suggested for use in the decaffeination of coffee. For the most part, such solvents comprise either single-phase organic liquids or two-phase mixtures of an organic liquid and water. Other art-disclosed processes involve the use of elevated temperatures and pressures in conjunction with solvents to promote rapid dissolution of the caffeine and its extraction from whole coffee beans.
A major problem with many potential decaffeination solvents is their ability not only to solubilize caffeine, but also to dissolve and remove important organic materials which account for the familiar coffee aroma and flavor. Of course, removal of such materials by a decaf solvent is preferably avoided to the extent possible.
The chlorinated hydrocarbon solvents are currently being used by most producers of decaffeinated coffee since they are cheap, relatively volatile, and rather easily recovered, once appropriate plant facilities are built. While caffeine is not particularly soluble in the chlorinated hydrocarbon solvents, as compared with other types of solvents, the economic advantage of the chlorinated hydrocarbons must be presumed, since they are in such wide commercial use. Importantly, the chlorinated hydrocarbons leave sufficient quantities of the flavor and aroma materials in the coffee so that decaffeinated coffee beverages with adequate (but suboptimal) flavor and aroma levels are secured.
The history of current government regulations indicates that there is some concern on the part of health care specialists regarding the use of chlorinated hydrocarbons to decaffeinate coffee. Residual levels of materials such as trichloroethylene have been judged to be intolerable in decaffeinated coffee, and the use of this material as a decaf solvent has recently been brought into question.
As can be seen from the foregoing, it would be advantageous to be able to remove caffeine from coffee without the need for chlorinated hydrocarbon solvents. Moreover, it would be highly desirable to use, as a decaffeination means, a caffeine solvent which is generally recognized as safe (GRAS) for food use. The use of a GRAS material as a solvent to decaffeinate coffee would alleviate any concerns about untoward physiological effects on the users of decaf products even if minor traces of the solvent were to remain therein.
It has now been determined that solvent systems comprising benzyl alcohol (a GRAS material) are quite effective in removing caffeine from coffee, and the like. Moreover, use of the benzyl alcohol systems does not result in unacceptable losses of organoleptically desirable flavor and aroma materials. Accordingly, the present invention provides a process for decaffeinating coffee, and like caffeine-containing materials, which employs benzyl alcohol as a caffeine solvent.